Features/Intel/AcpiDebugFeaturePkg: Add feature active PCD

Adds a dynamic PCD that specifies whether the feature is active.

This is useful because the feature might be enabled via FeatureFlag
PCD PcdAcpiDebugFeatureEnable meaning it is built and included in
the flash image but the board might need to control whether the
feature is active based on input such as a Setup menu option.

A deactivated feature will be dispatched but simply exit in the
entry point.

Cc: Sai Chaganty <rangasai.v.chaganty@intel.com>
Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Michael Kubacki <michael.a.kubacki@intel.com>
Reviewed-by: Sai Chaganty <rangasai.v.chaganty@intel.com>
Reviewed-by: Chasel Chiu <chasel.chiu@intel.com>